The authors say this is the first study that directly provides information about differences in longevity according to several modifiable factors.

It is well known that lifestyle factors, like being overweight, smoking and heavy drinking, predict death among elderly people. But is it uncertain whether these associations are applicable to people aged 75 years or more.

So a team of researchers based in Sweden measured the differences in survival among adults aged 75 and older based on modifiable factors such as lifestyle behaviours, leisure activities, and social networks.

Overall, the average survival of people with a low risk profile (healthy lifestyle behaviours, participation in at least one leisure activity, and a rich or moderate social network) was 5.4 years longer than those with a high risk profile (unhealthy lifestyle behaviours, no participation in leisure activities, and a limited or poor social network).

Even among those aged 85 years or older and people with chronic conditions, the average age at death was four years higher for those with a low risk profile compared with those with a high risk profile.

In summary, the associations between leisure activity, not smoking, and increased survival still existed in those aged 75 years or more, with women's lives prolonged by five years and men's by six years, say the authors.

These associations, although attenuated, were still present among people aged 85 or more and in those with chronic conditions, they add.

"Our results suggest that encouraging favourable lifestyle behaviours even at advanced ages may enhance life expectancy, probably by reducing morbidity," they conclude.